Electrical circuit diagram



Nov. 9, 1943. w RADFQRD 2,334,125

ELECTRICAL CIRCUIT DIAGRAM Filed July 2, 1941 J 7 9 1 4 if 9- 2 ,6 RECTIIIER 1N ,lnveuiol. JOILII/ 0/3. mww

Patented Nov. 9, 1943 2,334,125 niincrmcnn CIRCUIT DIAGRAM John Willi am Radfnrd, Th ayer ILL, assignor of onehalfto Dewayne Badford, Springfield, Ill} Application July 2, 1941,.senanroh40ms22 ejclai'm 1 (omit-32a),

j invention relates to meansforselectively, conveniently and .operativel'y controlling the flow of electric currentin electric: machines and especially in motion picture machines; an object beingtoprovide a control circuit for such pic"- ture machines as will permit the successful use of but one rectifier or generatbr'unitpossessing the same amperage output as has heretofore requiredthe service of two-of such units.

(a) The object of my electric current shifting control circuit is to! get the' same results from a "single: rectifier I or motor-generator;. of same amperage, instead of using-two rectifier units-or motor-generators of the same amperage output.

(1)) I attain these obj'ectsby using-the. electric By using a 30: ampere rectifier generator,

switch is closed, current flows through resistance l9, when change-over contact -switch .M'is

closed; making two complete paths of amperes each, or 20..ampe'res at are "3.. The current flow, producing 20. amperesat are" 13 is as follows: Ityfiows through resistancewunit'z. and. out at resistance'wire 3 connectsresistances 2 and [9. to double throw switch. 1; whilexwire. l0 connects: resistances E. and it to switch 8,

through resistanceunit 4 and out at resistance unit 3, byuswitch. [and contact 5, switch 'being' closed. Gontact l2, switch; 2.0 is; open.

current 'shifting' controlcircu it illustratedinthe accompanying drawing; as follows: I

The single figure is-an illustratiorrof'ian electrical control circuitfor' this invention, and with it, an illustration of essential electrical and: me-

chani'ca'l control membersoperativeiy. connected therewith. I

The figure in the drawing isan illustration oi a circuit diagram in cooperativexconnection with means for its:selective controll' i I" shall now describe my invention as I point out-tl'ie-essent'ial features of noveltyinrthe same.

Inmyinvention- I use for motion: picture service a pair of projecting lamps t'land I 33, connect'able" toa- 'sin'gle rectifier or generator member. l6" by"switches 8 and Iflrespectivelyand projecting the picture toa screen (not shown) throughopenings Wand I3: respectively; while an alternate useof lamps lfirand lril' willpermit cneilamp to bewarmedup whil'eitlle other is; on an operating. loadljust long enoughzaheadsof the load transfentcr letthev warmeduplamp be: ready tor; the sudden load: shock .without a. weakenin effect on the lamp and a possible; disturbance of the light. Thus in the figure'lamp I8 has the load, switch. 5 connecting resistance 4 with resistance 2 into the circuit between rectifier l6 and lamp l8 through switch l; but before lamp l8 was given the full load switch I was used as a warming up switch, using only resistance 2 for this warming up of lamp l8. In like manner lamp l1 willbe warmed up before a full load use by first throwing switch 6, using resistance 9 in the circuit between rectifier l6 and lamp i1, fol-' lowingwhioh the closing of switch I2 will put the full load on lamp I! using both resistance 9 and II for it; and permitting switch 5 to be pulled releasing lamp I8 until the warming up time for another load shift.

The operation of this invention is as follows:

at: resistance path. I; necessary at: are l1, forgprojeotiom, Switch rod Hi is pushed; to right. causing dowser ,B- to cover .Now 20' amperes. are light, is projected: through opening 13; to. screen,because dowser: 6 is open and; dowser It is. closed. Switchfi is open. The

change-overtakes place from are tB to'arc H, as

follows: H i v Switch 811sc1osed;.creating,-1O amperes at are I21; current fiows in resistance path 9 and, out Now twenty amperes is opening l3 and dowser 1- opens opening;v l'5, con- -tact Broil switch: 2!]- istopen contact t2 of switch 211 is closed adding luamperes more or a total ch20 amperesinstantaneously at arc I1. The

current-flowing through contact 42. switch,20 in resistance path H and'out. at resistance path 'Hirback' throughswitch 8 toarcll. Switch I is opened; arc I8. is out, but 20 amperes is still maintain 20 amperes at each arc.

maintained at. arc It, untilfchange-over takes place again at are I8; Then-switch Lis closed creating 10 amperesat arc--18. I 0 receivelO more; amperes atarc; l & or a total of 20 amperes necessary 'for projection at change-over, push switch rod to left again. This completes operation, 3

Thus: will be: obvious thatboth resistance unitsafor eachtlampwill need to be of equal resistance value in, order to permit a. free and balanced flow of current through them andback through the center tap between them; providing a uniform and balanced resistance for the lamp circuit when the two resistance units are thrown in for a full load on a projection lamp.

Under the past and present set-up in motion picture theatres, for instance to supply 20amperes for each arc, two 20 ampere rectifiers are necessary or one 20 ampere rectifier for each individual arc. If a motor-generator is used for are supply, 40 amperes output is necessary to Note the savings by using this electrical circuit."

1. Instead of usingtwo rectifiers, as is necestrical circuit.

power waste because it takes more power to supply a 40 ampere generator than a 30 ampere generator.

By using this electrical circuit with a gen- As only circuit terminals for said switches, a light shutter for each of said lamps, a common support for the shutters and said switches providing for their simultaneous operation, a pair. of electrical resistance units connected serially into the circuit with each of said arc lamps, and with both units of each pair alike in resistance value and each pair connected in parallel through a double pole single throw switch with said arclamps, i

and a center tap connection taken off the wire connection between said'res'ist ance units of each pairgeach lamp circuit having a direct connec+- tion from said center tap to its corresponding projectionfarc lamp, the remaining terminals of the resistance set being respectively connected 1 to said spaced circuit terminals, and a conneca amperegenerator will give the same results as a pe e ge erator, without this electrical circuit. Note the savings in initial-or installation costs of generator by using this elec- And also savings in operating expense. r

I claim: v 1. As a new electric circuit for motion picture projectorswhich are connected through a rectifying means with a source of-electric energy, a-pair of projection. arc lamps, a lamp circuit for each lamp, a pair of spaced switches, a pair of spacedcircuit-terminals for saidswitches, a light shutter'for each of said lamps, a common support for the shutters and said switchesproviding for their simultaneousoperation, a pair of electrical resistance units connected seriallyinto the'circuit with, each of said are lamps, and with both units of each pair-alike in resistance value and each a pair connected througha double pole single throw switch with in parallel said are lamps, and a center tap connection taken on the wire connection between said.re- 'sistance units of each pair, each lamp circuit having a direct connection from said center. tap toits corresponding projection'arc' lamp, the

remaining terminals of the resistance set'bein respectively connected to said spaced circuit terminals, and a connection between the projection arc lamps and'the power source of the rectifier controlled by said double pole single throw switch, the two sets of projection arc lamp circuits being connected in parallel electrically oil the power source through the rectifier, thus' 'permitting'one of said projection lamps to be struck on relatively low amperage resistance while the other isoperating at a higher level of resistance while both" are' securing their 'cur- 'rent from apower source through a single rectiiying means.

2. As a new electric circuit for motion picture projectors which are connected through a generator with a'source of electric energy, a pair of projection arc lamps, a lamp circuit for each lamp, a pair: of spaced switches, a pair of spaced tion between the projection arc lamps and a.

power source. of the generator controlled by said double pole single throw switch, the two sets of projection arc lamp circuits being connected in parallel electrically off. the power source through the generator, thuspermitting one of I said projectionlainps to ,be struck on relatively low amperage resistance while the other is operating at a higher level of=resistance and both are securing their current from a power source through a generator. 3. As a new electric circuit for pair of projection arclamps, a lampcircuiti'or each lamp, a pair'of spaced switches, a pair of spaced circuit terminals for said switches; a.

' light shutter for each, of said lamps, a common through the rectifier.

support for the shutters and said switchespro- 'viding'for their simultaneous operation, a pair of electrical resistance unitsconnected serially into the circuit with each of said are lamps, and with both units of each pairralike in. resistance value and each pair connected in parallel 'througha double pole single throw switch with said are lamps, and a center tap connection taken :off the wire connection between. said resistance units of eachrpair, each lamp circuit having a direct connection from said. center tap to its corresponding projection arc lamp, the remaining terminals of the resistance set beingrespectlvely connected to said spaced circuit terminals," and' a connection between the projectionarc lamps 1 and the power source of the rectifier controlled by said double pole single throwswitch, the two sets of projection arclamp circuits being connected in parallel electrically off the power-source through the rectifier, thus permitting one of said projection lamps to be struck on relatively low amperage resistance while the other is 0D-,. crating at a higher level 'of resistance while both are securing their currentfrom a power source JOHN WILLIAM RADFORD. V

. motion pi cture projectors which are connected through. a mercury arc with a source of electric-energy, a 

